Comparability of EBV-specific T cells generated using GMP-compliant reagents.
The SNBTS second generation EBV-specific T cell bank utilized some non-GMP standard reagents, including fetal bovine serum for LCL culture. We assessed whether EBV-specific T cell products cultured in GMP-compliant reagents including serum-free culture medium throughout would generate comparable T cell products. Culture was performed in G-Rex100 flasks using the optimized three-round stimulation protocol and assessment of T cell characteristics was carried out as before. In final product EBV-specific T cells grown in GMP compliant reagents throughout, surface phenotype (Figure 3A-3B) was substantially similar to those grown in research-grade reagents. A key improvement was a significantly higher percentage of TCM (CD62L+/ CD45RO+) cells in the GMP-compliant conditions (n=4).
There were no significant differences between the groups for cytokine co-expressing populations (Figure 3D), though a trend towards increased cytokine levels was observed in GMP-compliant cultures (Figure 3C). These data demonstrate that GMP compliant reagents used with G-Rex culture flasks results in EBV-specific T cell cultures that are comparable to current bank material, and have improved retention of the TCM compartment.